Offshore wind turbine systems and processes for installing same

Abstract

Offshore wind turbine systems and processes for installing same. The system can include a wind turbine generator that can include a plurality of blades connected thereto. The system can also include a first support arm and a second support arm each having a first end and a second end. The system can also include a support structure that can be configured to float on a surface of a body of water that can include first, second, and third columns. The first end of the first support arm and the first end of the second support arm can each support the wind turbine generator at an elevation above the support structure. The second end of the first support arm can be connected to and supported by the first column. The second end of the second support arm can be connected to and supported by the second column.

What is claimed is: 
     
         1 . An offshore wind turbine system, comprising:
 a wind turbine generator comprising a plurality of blades connected thereto;   a tower having a first end and a second end;   a first support arm and a second support arm each comprising a first end and a second end; and   a support structure configured to float on a surface of a body of water comprising a first column, a second column, and a third column, wherein:
 the first end of the tower supports the wind turbine generator at an elevation above the support structure, 
 the second end of the tower is supported by the first end of the first support arm and the first end of the second support arm, 
 the second end of the first support arm is connected to and supported by the first column, 
 the second end of the second support arm is connected to and supported by the second column, and 
 the system is free of a third support arm that supports the wind turbine generator. 
   
     
     
         2 . The system of  claim 1 , wherein the wind turbine generator is fixed in a stationary position relative to the first and second support arms. 
     
     
         3 . The system of  claim 1 , wherein the first support arm and the second support arm are each positioned between the plurality of blades and a central longitudinal axis extending from the third column. 
     
     
         4 . The system of  claim 1 , wherein the plurality of blades is positioned between a central longitudinal axis extending from the third column and the first and second support arms. 
     
     
         5 . The system of  claim 1 , wherein the first support arm and the second support arm each have a cross-sectional shape configured to reduce a wind induced drag load on the system and to facilitate rotative alignment of the support structure with a wind direction during operation of the wind turbine system. 
     
     
         6 . The system of  claim 1 , further comprising a ballast medium disposed within the support structure, wherein a volume of the ballast medium disposed within the support structure remains constant during operation of the wind turbine system. 
     
     
         7 . The system of  claim 6 , wherein a center of gravity of the ballast medium within the support structure remains constant during operation of the wind turbine system. 
     
     
         8 . The system of  claim 1 , wherein the wind turbine system is free of an active ballast control system configured to adjust a trim or a heel of the support structure during operation of the wind turbine system. 
     
     
         9 . The system of  claim 1 , wherein the wind turbine system is free of a ballast system configured to move a ballast medium from one of the first, second, or third columns of the support structure to another one of the first, second, or third columns of the support structure during operation of the wind turbine system. 
     
     
         10 . The system of  claim 1 , wherein the wind turbine generator is disposed within a nacelle, the system further comprising mechanical handling equipment disposed on or connected to the support structure, the first support arm, the second support arm, the nacelle, or a combination thereof, the mechanical handling equipment configured to facilitate installation, removal, or both installation and removal of the plurality of blades, the wind turbine generator, a gear box, a controller, a transformer, a rotor shaft, a brake assembly, or other component inside the nacelle when the support structure is floating on the surface of the body of water. 
     
     
         11 . The system of  claim 1 , further comprising a control system configured to adjust a pitch of the plurality of blades during operation. 
     
     
         12 . The system of  claim 1 , further comprising an anchor structure configured to be connected to the third column of the support structure and to a floor of the body of water, wherein, when the anchor structure is connected to the third column, the support structure is configured to passively rotate relative to the anchor structure to align the plurality of blades with a wind direction during operation of the wind turbine system. 
     
     
         13 . The system of  claim 12 , wherein a central longitudinal axis of the anchor structure is offset and parallel with a central longitudinal axis of the third column when connected thereto. 
     
     
         14 . The system of  claim 12 , further comprising a mooring structure rotatively connected to the third column of the support structure, wherein the mooring structure is configured to fixedly connect to the anchor structure, and wherein the mooring structure is configured to permit rotation of the support structure relative to the anchor structure. 
     
     
         15 . The system of  claim 12 , wherein the anchor structure comprises a fixed part and a rotating part rotatively connected together, wherein the rotating part of the anchor structure is configured to be connected to the third column of the support structure to permit rotation of the support structure relative to the fixed part of the anchor structure. 
     
     
         16 . The system of  claim 12 , wherein:
 the anchor structure comprises a buoyancy module, and   the buoyancy module forms part of the third column when the anchor structure and the mooring structure are connected to one another.   
     
     
         17 . The system of  claim 12 , further comprising a plurality of mooring legs each having a first end and a second end, wherein the first end of each mooring leg is configured to be connected to the anchor structure and the second end of each mooring leg is configured to be connected to the floor of the body of water. 
     
     
         18 . The system of  claim 1 , wherein the support structure is free of a fourth column. 
     
     
         19 . An offshore wind turbine system, comprising:
 a wind turbine generator comprising a plurality of blades connected thereto;   a first support arm and a second support arm each comprising a first end and a second end; and   a support structure configured to float on a surface of a body of water comprising a first column, a second column, and a third column, wherein:
 the first end of the first support arm and the first end of the second support arm each support the wind turbine generator at an elevation above the support structure, 
 the second end of the first support arm is connected to and supported by the first column, 
 the second end of the second support arm is connected to and supported by the second column, 
 the system is free of a third support arm that supports the wind turbine generator, 
 at least one of the first support arm and the second support arm further comprises an adjustable rudder disposed between the first end and the second end thereof, and 
 the adjustable rudder is incorporated into the at least one of the first support arm and that second support arm such that a longitudinal axis of the adjustable rudder is located within the at least one of the first support arm and the second support arm. 
   
     
     
         20 . An offshore wind turbine system, comprising:
 a wind turbine generator comprising a plurality of blades connected thereto;   a first support arm and a second support arm each comprising a first end and a second end;   a support structure configured to float on a surface of a body of water comprising a first column, a second column, and a third column, wherein:
 the first end of the first support arm and the first end of the second support arm each support the wind turbine generator at an elevation above the support structure, 
 the second end of the first support arm is connected to and supported by the first column, 
 the second end of the second support arm is connected to and supported by the second column, and 
 the system is free of a third support arm that supports the wind turbine generator; 
   an anchor structure configured to be connected to the third column of the support structure and to a floor of the body of water, wherein, when the anchor structure is connected to the third column, the support structure is configured to passively rotate relative to the anchor structure to align the plurality of blades with a wind direction during operation of the wind turbine system;   an electrical slip ring comprising a fixed part and a rotating part rotatively connected together, wherein the fixed part of the electrical slip ring is connected to the anchor structure, wherein the rotating part of the electrical slip ring is connected to the support structure, and wherein the electrical slip ring is configured to maintain electrical continuity between the fixed part and the rotating part during rotation therebetween; and   a first cable comprising a first end configured to be electrically connected to the wind turbine generator and a second end configured to be electrically connected to the rotating part of the electrical slip ring, wherein the offshore wind turbine system is configured to receive and support a second cable comprising a first end configured to be releasably connected to the fixed part of the electrical slip ring and a second end configured to be connected to a facility configured to receive electrical power generated by the wind turbine such that the wind turbine is configured to be electrically connected to the facility when the first end of the second cable is connected to the fixed part of the electrical slip ring and the second end of the second cable is connected to the facility.   
     
     
         21 . The system of  claim 20 , further comprising a tower having a first end and a second end, wherein the first end of the tower supports the wind turbine generator and the second end of the tower is supported by the first end of the first support arm and the first end of the second support arm. 
     
     
         22 . The system of  claim 20 , wherein the plurality of blades is positioned between a central longitudinal axis extending from the third column and the first and second support arms. 
     
     
         23 . The system of  claim 20 , wherein a central longitudinal axis of the anchor structure is offset and parallel with a central longitudinal axis of the third column when connected thereto. 
     
     
         24 . An offshore wind turbine system, comprising:
 a wind turbine generator comprising a plurality of blades connected thereto;   a first support arm and a second support arm each comprising a first end and a second end; and   a support structure configured to float on a surface of a body of water comprising a first column, a second column, and a third column, wherein:
 the first and second support arms each comprise a first section and a second section, 
 a first end of the first section of the first and second support arms each support the wind turbine generator at an elevation above the support structure, 
 a second end of the first section of the first and second support arms is connected to a first end of the second section of the first and second support arms, respectively, 
 a second end of the second section of the first and second support arms is connected to and supported by the first and second columns, respectively, 
 the first sections of the first and second support arms form an A-frame type configuration, 
 the second sections of the first and second support arms extend away from the first and second columns, respectively, in a substantially vertical direction such that the second sections of the first and second support arms are oriented within 15 degrees of an axis that is vertical with respect to a central longitudinal axis of the first and second columns, respectively, and 
 the system is free of a third support arm that supports the wind turbine generator.